The emission beyond the light cylinder might be essential.
[1]} showed that the ideal-MHD condition breaks down
beyond the Y-point, the open-close boundary on the light cylinder.
He showed that a wedge shaped region beyond the Y-point
is electric field dominant, \(|E| >|B|\) , and
the force-free approximation is no longer applicable there.
This region indeed appears in particle simulations
, .
It has been suggested that the location of the Y-point is a free
parameter for the force-free model
[2]}. This fact alone might indicate that the Y-point shift outward so that
the lever arm becomes larger than the light cylinder radius.
However, as was suggested by [3]} and seen in
Fig. REF  as well as in the numerical simulation
, ,
the region around the
open-close boundary is super-corotation, and hence
the Y-point shifts inwards.
The particle acceleration and radiation in the vicinity of the Y-point
will not contribute to the efficient loss of the angular momentum,
but the current sheet beyond the light cylinder will do.
Some indication may be found in numerical simulations
(e.g., [4]}).
